What is the amplitude of $g(x)=-2\sin\left(\dfrac{\pi}{2} x-3\right)+5$ ?
Explanation: Amplitude in sinusoids of the form $f(x)=a\sin(bx+c)+d$ The amplitude of a sinusoid of the form $f(x)={a}\sin(bx + c) + d$ is equal to $|{a}|$. [How can we justify this given our graphical understanding of amplitude?] Finding the amplitude The amplitude of $g(x)={-2}\sin\left(\dfrac{\pi}{2} x-3\right)+5$ is $|{-2}|=2$.